The Columbia Encyclopedia, Sixth Edition. 2001.
Praetorians
(prtôrŽnz) (KEY) , bodyguard of the ancient
Roman emperors. Growing out of an early troop that served as bodyguard to
the general commanding in Rome, they were formally organized in the time of
Augustus. The number of cohorts (from 500 to 1,000 men each) forming the guard
varied, but in the days of the later empire it was 10. The Praetorians under
a prefect attended the emperor wherever he went. They had special privileges
and, in the period when the empire declined, held almost unchallenged authority.
Constantine I disbanded them in 312.